The purpose of this snippet is to prepare all arguments for __libc_start_main, which performs all the necessary initialization before the main() routine of our C/C++-code is called. The prototype of __libc_start_main is:

This causes the program to exit with exit code 1, I therefore renamed this location as exit in IDA Pro. Exiting at this point probably means that the pseudo/clef combination is invalid, and we know that clef needs to have 6 letters.

a different subroutine gets called, I renamed it as func_2. The first parameter to func_2 is pseudo, the second parameter is the pseudo_length = strlen(pseudo).

the instruction inc edi makes edi reference clef[1].

There’s one pitfall: Because of the preceeding push edi in the second line, [esp+8] points to pseudo, and not clef as you might expect. Be careful when interpreting stack references based on esp rather than ebp.